To meet the demand for wireless data traffic having increased since deployment of 4G (4th-Generation) communication systems, efforts have been made to develop an improved 5G (5th-Generation) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘beyond 4G network’ or a ‘post LTE system’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like.
In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
A handover refers to functionality allowing a terminal relocating from the service coverage of a base station to the service coverage of another base station to remain connected for service while syncing with a call channel assigned to the service coverage of the other base station. The term “handover” may also be referred to as “handoff.”
A handover typically occurs when a terminal disconnects from a network currently in connection or switches the connection from the network to another network with a higher priority. This is described in greater detail with reference to the drawings.
FIG. 1 is a view illustrating an example in which a handover occurs as a terminal disconnects from a network according to the related art.
Referring to FIG. 1, the terminal 101 downloads contents 120 from its connecting server 102 through the network 1 103 (e.g., a wi-fi network) (110). For various reasons, the terminal 101 may disconnect from the network 1 103 (112). In this case, the terminal 101 might fail to receive all of the contents 120, and instead receive only some of the contents 122, through the network 1 103. The terminal 101 may not connect to the network 1 103 and discover other networks. When the terminal 101 discovers a network 2 104 (e.g., an LTE network), the terminal 101 attempts to establish a connection 114 with the network 2 104. When the terminal 101 connects with the network 2 104, the terminal 101 downloads the rest 126 of the contents 120.
FIG. 2 is a view illustrating an example in which a handover occurs as a terminal connects to a network with a higher priority than that of the network that the terminal is currently in connection with according to the related art.
Referring to FIG. 2, it is first assumed that the network 1 203 (e.g., a wi-fi network) is higher in priority than the network 2 204 (e.g., an LTE network). As described above in connection with FIG. 1, the terminal 201 likewise downloads contents 220 from its connecting server 202 through the network 2 204 (210). The terminal 201 may discover other networks while downloading the contents 220. When the terminal 201 discovers the network 1 203 with a higher priority than that of the network 2 204, the terminal 201 attempts to connect with the network 1 203 (212). When the terminal 201 connects with the network 1 203, the terminal 201 disconnects from the network 2 204 (214). When the terminal 201 downloaded only some 222 of the contents through the network 2 204, the terminal 201 downloads the remaining contents 226 through the network 1 203.
Such handover scheme releases connection with a current network before establishing a connection with a new network and is thus inefficient due to a reduction in data transmission rate upon handover. According to the present disclosure, there is suggested a handover method supportive of a high data transmission rate even during a handover.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.